复制代码代码如下:

< script type="text/javascript" >

//使用apply方法实现对象继承

function Parent(username) {

this.username = username;

this.sayHello = function() {

alert(this.username);

}

}

function Child(username, password) {

Parent.apply(this, new Array(username));

//和下面一样

//Parent.apply(this, [username]);

this.password = password;

this.sayWorld = function() {

alert(this.password);

}

}

var parent = new Parent("zhangsan");

var child = new Child("lisi", "123");

parent.sayHello();

child.sayHello();

child.sayWorld();

< /script >